1. Field of the Invention
The present invention relates to security and anti-theft devices. More particularly, it relates to a supervised anti-theft security system for consumer product displays.
2. The Prior Art
Anti-theft security systems are commonly used in many retail establishments, especially those that sell expensive and easily portable items such as consumer electronics. One way to prevent theft of the item is to physically lock it to a permanent surface via a cable lock. However, this does not prevent a thief from cutting the cable to steal the item. Another technique is a magnetized tag affixed to the item. When the thief attempts to leave the store with the item, he passes through magnetized gates which set off an alarm if the tag passes through.
Some security systems are a combination of physical restraint and electronic alarm. U.S. Pat. No. 5,821,857 to Rand, the disclosure of which is herein incorporated by reference, discloses an anti-theft security system having a command module and a plurality of sensor satellites arranged in a daisy chain configuration. The command module and sensor satellites operate with microprocessors. Each sensor satellite can receive up to 8 sensors each, so many different items can be monitored. No shunts or terminators are required for the unused jacks. Each sensor is attached to an item to be monitored. Cutting the wire or removing the sensor from the item causes an alarm to sound from the central command module.
While this device has many benefits, it does not protect the merchandise from being stolen by shorting the circuit by placing a pin through the wire, because the central command module cannot sense this change.